Optical system and method of operating an optical system

Abstract

The application provides an optical system and a working method of the optical system. The optical system comprises: a first incident light configured to be incident to a surface of a sample at a first incident angle along a first light path; and a first adjustable mirror configured to cause a second incident light to be incident to the surface of the sample at a second incident angle along a second light path, and to cause the second incident light to be incident to the surface of the sample at the first incident angle along the first light path, the first incident angle being different from the second incident angle.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and more specifically to an optical system and a method for operating the optical system. Background Technology

[0002] In sample defect detection, different defects on the sample surface have different sensitivities to detection beams with different incident directions. To prevent missed detections, it is necessary to use detection beams with different incident directions. Furthermore, to detect different types of defects, it is sometimes necessary to use detection beams with different wavelengths or polarizations for incident illumination. This results in a complex incident optical path, a large number of optical components, and high costs. Summary of the Invention

[0003] The purpose of this application is to provide an optical system that simplifies the optical path structure and reduces costs.

[0004] To address the aforementioned technical problems, the present invention provides an optical system comprising: a first incident light configured to be incident on the surface of a sample along a first optical path at a first incident angle; a first adjustable mirror configured to cause a second incident light to be incident on the surface of the sample along a second optical path at a second incident angle, the first adjustable mirror further configured to cause the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle, wherein the first incident angle and the second incident angle are different.

[0005] Optionally, the second incident light is used to be reflected by the first adjustable mirror and then incident on the surface of the sample along the second optical path at the second incident angle; or, the second incident light is used to bypass the first adjustable mirror and then incident on the surface of the sample along the second optical path at the second incident angle; the second incident light is also used to be reflected by the first adjustable mirror and then incident on the surface of the sample along the first optical path at the first incident angle; or, the second incident light is also used to bypass the first adjustable mirror and then incident on the surface of the sample along the first optical path at the first incident angle.

[0006] Optionally, it further includes: a second adjustable mirror, the second adjustable mirror being used to cause the first incident light to be incident on the surface of the sample along the first optical path at a first incident angle, the second adjustable mirror being further used to cause the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle; wherein, the position of the first adjustable mirror in the second optical path is a second position, and the position of the second adjustable mirror in the first optical path is a first position.

[0007] Optionally, the second adjustable mirror is further configured to allow the first incident light to be incident at the second position, and the first adjustable mirror is further configured to allow the first incident light incident at the second position to be incident on the surface of the sample along the second optical path at a second incident angle; specifically, the first adjustable mirror is configured to allow the second incident light to be incident at the first position, and then the second incident light to be incident on the surface of the sample along the first optical path at a first incident angle; specifically, the second adjustable mirror is configured to allow the first incident light to be incident at the second position, and then the first incident light to be incident on the surface of the sample along the second optical path at a second incident angle.

[0008] Optionally, both the first and second adjustable mirrors are reflectors. The first and second incident light rays have different incident directions when incident on the first position, and the exit direction of the second incident light along the first optical path after incident on the first position is different from the incident direction of the first incident light at the first position. The second adjustable mirror can be rotated to cause the first incident light to incident on the sample surface along the first optical path at a first incident angle, or to cause the second incident light to incident on the sample surface along the first optical path at a first incident angle; or, the first incident light, after incident on the first position, exits along the first optical path at a first incident angle. The exit direction of the path is the same as the incident direction of the second incident light at the first position. The second adjustable mirror moves to cause the first incident light to be incident on the sample surface along the first optical path at a first incident angle, or to cause the second incident light to be incident on the sample surface along the first optical path at a first incident angle. The first adjustable mirror is used to move or rotate to cause the second incident light to be incident on the sample surface along the second optical path at a second incident angle, or to cause the second incident light to be incident on the sample surface along the first optical path at the first incident angle after being incident on the first position; and / or, The first incident light and the second incident light have different incident directions when they are incident on the second position, and the exit direction of the first incident light along the second optical path after it is incident on the second position is different from the incident direction of the second incident light at the second position. The first adjustable mirror rotates to make the first incident light incident on the sample surface along the second optical path at a second incident angle or to make the second incident light incident on the sample surface along the second optical path at a second incident angle; or, the exit direction of the first incident light along the second optical path after it is incident on the second position is the same as the incident direction of the second incident light at the second position. The first adjustable mirror moves to make the first incident light incident on the sample surface along the second optical path at a second incident angle or to make the second incident light incident on the sample surface along the second optical path at a second incident angle; the second adjustable mirror is used to move or rotate to make the first incident light incident on the sample surface along the first optical path at a first incident angle, or to make the first incident light incident on the sample surface along the second optical path at a second incident angle after it is incident on the second position.

[0009] Optionally, if the first adjustable mirror is in the first state and the second adjustable mirror is in the second state, the second incident light is incident on the sample surface along the second optical path at the second incident angle, and the first incident light is incident on the sample surface along the first optical path at the first incident angle; if the first adjustable mirror is in the third state and the second adjustable mirror is in the fourth state, the first incident light is incident on the sample surface along the second optical path at the second incident angle, and the second incident light is incident on the sample surface along the first optical path at the first incident angle.

[0010] Optionally, if the first incident light and the second incident light have different incident directions when incident on the first position, and the exit direction of the second incident light along the first optical path after incident on the first position is different from the incident direction of the first incident light at the first position, the second adjustable mirror can be rotated; if the second adjustable mirror is at a first angle in the first optical path, the second adjustable mirror is used to cause the first incident light to be reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle; if the second adjustable mirror is at a second angle in the first optical path, the second adjustable mirror is used to cause the second incident light to be reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle, the second angle being perpendicular to the first angle or having an acute angle; the second adjustable mirror can also be moved, if the second adjustable mirror moves out of the first optical path, the first incident light bypasses the second adjustable mirror and is incident on the second position; or, if the second adjustable mirror is at a third angle, the second adjustable mirror is used to cause the first incident light to be incident on the second position; and / or, If the first incident light and the second incident light have different incident directions when incident on the second position, and the exit direction of the first incident light along the second optical path after incident on the second position is different from the incident direction of the second incident light at the second position, the first adjustable mirror can be rotated; if the first adjustable mirror is at the fourth angle in the second optical path, the first adjustable mirror is used to make the second incident light, after being reflected by the first adjustable mirror, incident on the sample surface along the second optical path at the second incident angle; if the first adjustable mirror is at the fifth angle in the second optical path, the first adjustable mirror is used to make the first incident light, after being reflected by the first adjustable mirror, incident on the sample surface along the second optical path at the second incident angle, wherein the fourth angle and the fifth angle are perpendicular or have an acute angle; the first adjustable mirror can also be moved, if the first adjustable mirror moves out of the second optical path, the second incident light bypasses the first adjustable mirror and incident on the first position; or, if the first adjustable mirror is at the sixth angle, the first adjustable mirror is used to make the second incident light incident on the first position.

[0011] Optionally, the first incident light and the second incident light have different incident directions when incident on the first position. The exit direction of the first incident light along the first optical path after incident on the first position is the same as the incident direction of the second incident light when incident on the first position. The second adjustable mirror, by entering and exiting the optical path, causes the first incident light to be incident on the sample surface along the first optical path at a first incident angle, or causes the second incident light to be incident on the sample surface along the first optical path at a first incident angle. Alternatively, the first incident light and the second incident light have the same but staggered incident directions when incident on the second adjustable mirror. The second adjustable mirror, by switching the incident directions of the first and second incident lights, causes the first incident light to be incident on the sample surface along the first optical path at a first incident angle, or causes the second incident light to be incident on the sample surface along the first optical path at a first incident angle. The first adjustable mirror is used to move to cause the first incident light to be incident on the sample surface along the second optical path at a second incident angle, or to cause the second incident light to be incident on the sample surface along the second optical path at a second incident angle. And / or, The first incident light and the second incident light have different incident directions when incident on the second position. After the first incident light is incident on the second position, its exit direction along the second optical path is the same as the incident direction of the second incident light when incident on the second position. The first adjustable mirror causes the first incident light to be incident on the sample surface along the second optical path at a second incident angle or causes the second incident light to be incident on the sample surface along the second optical path at a second incident angle by entering and exiting the optical path. Alternatively, the first incident light and the second incident light are incident on the first adjustable mirror in the same but staggered directions. The first adjustable mirror causes the first incident light to be incident on the sample surface along the second optical path at a second incident angle or causes the second incident light to be incident on the sample surface along the second optical path at a second incident angle by switching the incident directions of the first incident light and the second incident light. The second adjustable mirror is used to move to cause the first incident light to be incident on the sample surface along the first optical path at a first incident angle or to cause the second incident light to be incident on the sample surface along the first optical path at a first incident angle by moving it.

[0012] Optionally, the first incident light and the second incident light are incident on the second adjustable mirror in the same but staggered directions, and / or the first incident light and the second incident light are incident on the first adjustable mirror in the same but staggered directions; the first state is that the first adjustable mirror is located in the optical path of the second incident light, and the second state is that the second adjustable mirror is located in the optical path of the first incident light; the second incident light is reflected by the first adjustable mirror and then incident on the sample surface along the second optical path at a second incident angle, and the first incident light is reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle; the third state is that the first adjustable mirror is located in the optical path of the first incident light, and the fourth state is that the second adjustable mirror is located in the optical path of the second incident light, the first incident light is reflected by the first adjustable mirror and then incident on the sample surface along the second optical path at a second incident angle, and the second incident light is reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle.

[0013] Optionally, the first incident light and the second incident light have different incident directions when incident on the first position, and the exit direction of the first incident light along the first optical path after incident on the first position is the same as the incident direction of the second incident light when incident on the first position; and / or, the first incident light and the second incident light have different incident directions when incident on the second position, and the exit direction of the first incident light along the second optical path after incident on the second position is the same as the incident direction of the second incident light when incident on the second position; the first state is the first adjustable mirror moving out of the second position, and the second state is the second adjustable mirror position. In the first position, the second incident light bypasses the first adjustable mirror and then enters the sample surface along the second optical path at a second incident angle, and the first incident light is reflected by the second adjustable mirror and then enters the sample surface along the first optical path at a first incident angle; the third state is that the first adjustable mirror is located in the second position; the fourth state is that the second adjustable mirror moves out of the first position, the first incident light bypasses the second adjustable mirror and then enters the sample surface along the second optical path at a second incident angle, and the second incident light is reflected by the second adjustable mirror and then enters the sample surface along the first optical path at a first incident angle.

[0014] Optionally, the optical system further includes one or a combination of a first reflective element and a second reflective element. If the first adjustable mirror moves out of the second position, the second incident light is incident on the second reflective element and then reflected by the second reflective element before being incident on the sample surface along the second optical path at a second incident angle. If the second adjustable mirror moves out of the first position, the second incident light is incident on the first reflective element and then reflected by the first reflective element before being incident on the sample surface along the first optical path at a first incident angle.

[0015] Optionally, it further includes: a first directional lens group, located in the first optical path between the second adjustable lens and the sample, for directing the first incident light or the second incident light onto the surface of the sample at a first incident angle; a second directional lens group, located in the second optical path between the first adjustable lens and the sample, for directing the first incident light or the second incident light onto the surface of the sample at a second incident angle; a third directional lens group, the third directional lens group being used to direct the second incident light onto the first position, and the third directional lens group also being used to direct the first incident light onto the second position; or, the third directional lens group being used to adjust the transmission direction of the first incident light or the second incident light so that the first incident light or the second incident light is transmitted to the surface of the sample.

[0016] Optionally, it further includes: a first shaping element located in a first optical path between the second adjustable mirror and the sample; and a second shaping element located in a second optical path between the first adjustable mirror and the sample.

[0017] Optionally, the optical system may further include one or more detectors, the optical axes of which are perpendicular to the sample surface or have an acute angle with the sample surface normal.

[0018] The present invention also provides a method for operating an optical system based on the present invention, comprising: causing a first incident light to be incident on the surface of a sample along a first optical path at a first incident angle; causing a second incident light to be incident on the surface of the sample along a second optical path at a second incident angle through a first adjustable mirror, and causing the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle through the first adjustable mirror, wherein the first incident angle and the second incident angle are different.

[0019] Optionally, it further includes: a second adjustable mirror; the second adjustable mirror causes the first incident light to be incident on the surface of the sample along the first optical path at a first incident angle, and the second adjustable mirror causes the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle; wherein, the position of the second adjustable mirror in the first optical path is a first position, and the position of the first adjustable mirror in the second optical path is a second position.

[0020] Optionally, directing the second incident light along the first optical path to the surface of the sample at the first incident angle via the first adjustable mirror includes: after directing the second incident light to a first position via the first adjustable mirror, the second incident light is directed along the first optical path to the surface of the sample at the first incident angle; directing the first incident light along the second optical path to the surface of the sample at the second incident angle via the second adjustable mirror includes: after directing the first incident light to a second position via the second adjustable mirror, the first incident light is directed along the second optical path to the surface of the sample at the second incident angle.

[0021] Optionally, if the first incident light and the second incident light have different incident directions when incident on the first position, and the exit direction of the second incident light along the first optical path after incident on the first position is different from the incident direction of the first incident light at the first position, the second adjustable mirror can be rotated; causing the first incident light to be incident on the sample surface along the first optical path at a first incident angle via the second adjustable mirror includes: moving the second adjustable mirror into the first optical path and placing it at a first angle, and the first incident light being reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle; causing the second incident light to be incident on the sample surface along the first optical path at a first incident angle via the second adjustable mirror includes: moving the second adjustable mirror into the first optical path and placing it at a second angle, and the second incident light being incident on the sample surface along the first optical path at a first incident angle after reflection by the second adjustable mirror; causing the first incident light to be incident on the sample surface along the second optical path at a second incident angle via the second adjustable mirror. The surface of the sample includes: positioning the second adjustable mirror at a third angle in the first optical path, the first incident light being reflected by the second adjustable mirror and incident at the second position, and then the first incident light incident on the sample surface along the second optical path at a second incident angle; the second adjustable mirror can also be moved, and causing the first incident light to incident on the sample surface along the second optical path at the second incident angle via the second adjustable mirror includes: moving the second adjustable mirror out of the first optical path, the first incident light bypassing the second adjustable mirror and incident at the second position, and then the first incident light incident on the sample surface along the second optical path at the second incident angle; or, causing the first incident light to incident on the sample surface along the first optical path at the first incident angle via the second adjustable mirror includes: moving the second adjustable mirror out of the first optical path, the first incident light bypassing the second adjustable mirror and then incident on the sample surface along the first optical path at the first incident angle; and / or If the incident directions of the first incident light and the second incident light are different when they are incident on the second position, and the exit direction of the first incident light along the second optical path after it is incident on the second position is different from the incident direction of the second incident light at the second position, the first adjustable mirror can be rotated; causing the second incident light to be incident on the sample surface along the second optical path at a second incident angle via the first adjustable mirror includes: moving the first adjustable mirror into the second optical path and placing it at a fourth angle, and the second incident light being reflected by the first adjustable mirror and then incident on the sample surface along the second optical path at a second incident angle; causing the first incident light to be incident on the sample surface along the second optical path at a second incident angle via the first adjustable mirror includes: moving the first adjustable mirror into the second optical path and placing it at a fifth angle, and the first incident light being incident on the sample surface along the second optical path at a second incident angle after being reflected by the first adjustable mirror; causing the second incident light to be incident on the sample surface along the first optical path at a first incident angle via the first adjustable mirror. The surface of the sample includes: positioning the first adjustable mirror at a sixth angle in the second optical path, the second incident light being reflected by the first adjustable mirror and incident at the first position, and then the second incident light incident on the surface of the sample along the first optical path at a first incident angle; the first adjustable mirror can also be moved, and causing the second incident light to incident on the surface of the sample along the first optical path at the first incident angle through the first adjustable mirror includes: moving the first adjustable mirror out of the second optical path, the second incident light bypassing the first adjustable mirror and incident at the first position, and then the second incident light incident on the surface of the sample along the first optical path at the first incident angle; or, causing the second incident light to incident on the surface of the sample along the second optical path at the second incident angle through the first adjustable mirror includes: moving the first adjustable mirror out of the second optical path, the second incident light bypassing the first adjustable mirror and then incident on the surface of the sample along the second optical path at the second incident angle.

[0022] Optionally, if the exit direction of the first incident light along the first optical path after it is incident on the first position is the same as the incident direction of the second incident light when it is incident on the first position; and / or, the exit direction of the first incident light along the second optical path after it is incident on the second position is the same as the incident direction of the second incident light when it is incident on the second position; the first adjustable mirror is in a first state, the second adjustable mirror is in a second state, and the first incident light is incident on the surface of the sample along the first optical path at a first incident angle through the second adjustable mirror, while the second incident light is incident on the surface of the sample along the second optical path at a second incident angle through the first adjustable mirror; the first adjustable mirror is in a third state, the second adjustable mirror is in a fourth state, and the second incident light is incident on the surface of the sample along the first optical path at a first incident angle through the second adjustable mirror, while the first incident light is incident on the surface of the sample along the second optical path at a second incident angle through the first adjustable mirror.

[0023] The technical solution of this invention has the following technical effects: The optical system provided by this invention configures a first incident light to be incident on the surface of a sample along a first optical path at a first incident angle. An adjustable mirror is used to allow a second incident light to be incident on the surface of the sample along a second optical path at a second incident angle. The first and second incident angles are different, enabling different incident lights to be incident on the surface of the sample at different incident angles. This allows the optical response of the sample at different incident angles to be acquired, enabling comprehensive detection of the sample surface and preventing missed detections. The adjustable mirror is also used to allow the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle. The adjustable mirror enables the switching of different incident angles for the same incident light (the second incident light can be incident on the sample surface at either the first or second incident angle) and allows different incident lights to share the same optical path (when incident on the sample surface at the first incident angle, the first and second incident lights share the first optical path), simplifying the optical path structure. At the same time, it avoids the use of similar optical components, reducing costs. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figures 1 to 3 This is a schematic diagram of the optical system provided in the first embodiment of the present invention; Figure 4 This is a schematic diagram of the optical system provided in the second embodiment of the present invention; Figures 5 to 6 This is a schematic diagram of the optical system provided in the third embodiment of the present invention; Figures 7 to 8 This is a schematic diagram of the optical system provided in the fourth embodiment of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Reference Figures 1 to 8 This embodiment provides an optical system, including: a first incident light A configured to be incident on the surface of a sample 1 along a first optical path at a first incident angle; a first adjustable mirror 22, the first adjustable mirror 22 being used to cause a second incident light B to be incident on the surface of the sample 1 along a second optical path at a second incident angle, the first adjustable mirror 22 also being used to cause the second incident light B to be incident on the surface of the sample 1 along the first optical path at a first incident angle, the first incident angle and the second incident angle being different.

[0031] In this embodiment, the first incident light A is configured to be incident on the surface of sample 1 along the first optical path at a first incident angle. The first adjustable mirror 22 is used to cause the second incident light B to be incident on the surface of sample 1 along the second optical path at a second incident angle. The first incident angle and the second incident angle are different, realizing that different incident lights are incident on the surface of sample 1 at different incident angles. The optical response of sample 1 at different incident angles can be obtained so as to perform all-round detection of the surface of sample 1 and prevent missed detection. The first adjustable mirror 22 is also used to cause the second incident light B to be incident on the surface of sample 1 along the first optical path at a first incident angle. The first adjustable mirror 22 realizes the function of "the same incident light can switch different incident angles (the second incident light B is incident on the surface of sample 1 at the first incident angle or the second incident angle) and different incident lights can share the same optical path (when incident on the surface of sample 1 at the first incident angle, the first incident light A and the second incident light B share the first optical path", which simplifies the optical path structure. At the same time, it avoids the use of similar optical elements and reduces costs.

[0032] Specifically, the second incident light B is used to be reflected by the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at a second incident angle; or, the second incident light B is used to bypass the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at a second incident angle. The second incident light B is also used to be reflected by the first adjustable mirror 22 and then incident on the surface of sample 1 along the first optical path at a first incident angle; or, the second incident light B is also used to bypass the first adjustable mirror 22 and then incident on the surface of sample 1 along the first optical path at a first incident angle. It is understood that when the second incident light B is reflected by the first adjustable mirror 22, the first adjustable mirror 22 enters the optical path; when the second incident light B bypasses the first adjustable mirror 22, the first adjustable mirror 22 moves out of the optical path.

[0033] For example, the first angle of incidence is 0 degrees and the second angle of incidence is 90 degrees. In other embodiments, the first angle of incidence can be other angles, and the second angle of incidence can be other angles.

[0034] In this embodiment, the optical system further includes a second adjustable mirror 21. The second adjustable mirror 21 is used to direct the first incident light A along the first optical path to the surface of the sample 1 at a first incident angle. The second adjustable mirror 21 is also used to direct the second incident light B along the first optical path to the surface of the sample 1 at a first incident angle. The second adjustable mirror 21 enables different incident lights to be incident on the surface of the sample 1 at the same incident angle, thereby helping to eliminate errors and improve detection accuracy. Simultaneously, the second adjustable mirror 21 allows the first incident light A and the second incident light B to share the first optical path, simplifying the optical path structure. Furthermore, it avoids the use of similar optical components, reducing costs.

[0035] Specifically, the first incident light A is reflected by the second adjustable mirror 21 and then incident on the surface of sample 1 along the first optical path at a first incident angle; alternatively, the first incident light A is bypassed by the second adjustable mirror 21 and then incident on the surface of the sample along the first optical path at a first incident angle. The second incident light B is reflected by the second adjustable mirror 21 and then incident on the surface of sample 1 along the first optical path at a first incident angle. It is understood that when the first incident light A and the second incident light B are reflected by the second adjustable mirror 21, the second adjustable mirror 21 enters the optical path; when the first incident light A is bypassed by the second adjustable mirror 21, the second adjustable mirror 21 moves out of the optical path.

[0036] In this embodiment, the position of the first adjustable mirror 22 in the second optical path is the second position F, and the position of the second adjustable mirror 21 in the first optical path is the first position M.

[0037] In this embodiment, both the first adjustable mirror and the second adjustable mirror are reflectors; the incident directions of the first incident light and the second incident light are different when they are incident on the first position, and the exit direction of the second incident light along the first optical path after it is incident on the first position is different from the incident direction of the first incident light at the first position. The second adjustable mirror is rotated to make the first incident light incident on the sample surface along the first optical path at a first incident angle or to make the second incident light incident on the sample surface along the first optical path at a first incident angle; or, the exit direction of the first incident light along the first optical path after it is incident on the first position is the same as the incident direction of the second incident light at the first position. The second adjustable mirror is moved to make the first incident light incident on the sample surface along the first optical path at a first incident angle or to make the second incident light incident on the sample surface along the first optical path at a first incident angle. Through the coordinated operation of the first and second adjustable mirrors, the second adjustable mirror flexibly adopts rotation or movement strategies according to the different situations where the first and second incident lights are incident at the first position. Combined with the optical path operation of the first adjustable mirror, it realizes the free and precise switching of the second incident light between the first and second optical paths, simplifying the optical path structure and improving the detection accuracy.

[0038] In this embodiment, the second adjustable mirror 21 is further used to direct the first incident light B to the second position, and the first adjustable mirror is further used to direct the first incident light B, which is incident at the second position, to the surface of sample 1 along the second optical path at a second incident angle. Through the cooperation of the second adjustable mirror 21 and the first adjustable mirror 22, different incident lights are directed to the surface of sample 1 at different angles. The first incident light A can be directed to the surface of sample 1 at either the second or first incident angle, and similarly, the second incident light B can be directed to the surface of sample 1 at either the second or first incident angle. Furthermore, the first incident light A and the second incident light B can share either the first or second optical path. This ensures comprehensive detection of the surface of sample 1 while avoiding the use of similar optical components, thus reducing costs. Meanwhile, the second adjustable mirror 21 achieves the function of "changing the first incident light A to be incident on the surface of sample 1 at a first incident angle or a second incident angle, and the first incident light A and the second incident light B sharing a second optical path", thus simplifying the optical path structure.

[0039] Furthermore, the first adjustable mirror 22 is specifically used to cause the second incident light B to be incident on the surface of the sample 1 along the first optical path at the first incident angle after the second incident light B is incident on the first position M; the second adjustable mirror 21 is specifically used to cause the first incident light A to be incident on the surface of the sample 1 along the second optical path at the second incident angle after the first incident light A is incident on the second position F.

[0040] Specifically, the second incident light B is used to bypass the first adjustable mirror 22 and then be incident on the first position M, or the second incident light B is used to be incident on the first position M after being reflected by the first adjustable mirror 22, or the second incident light B is used to be incident directly on the first position M. After the second incident light B is incident on the first position M, the second adjustable mirror 21 reflects the second incident light B and then incident it on the surface of the sample 1 along the first optical path at the first incident angle; the first incident light A is used to bypass the second adjustable mirror 21 and then be incident on the second position F, or the first incident light A is used to be incident on the second position F after being reflected by the second adjustable mirror 21, or the first incident light A is used to be incident directly on the second position F. After the first incident light A is incident on the second position F, the first adjustable mirror 22 reflects the first incident light A and then incident it on the surface of the sample 1 along the second optical path at the second incident angle.

[0041] In this embodiment, the first incident light A and the second incident light B have different wavelengths or polarizations. The first incident light A and the second incident light B with different wavelengths or polarizations can detect different types of defects on the surface of sample 1.

[0042] In this embodiment, both the first adjustable mirror 22 and the second adjustable mirror 21 are reflectors. The light from the first incident light A and the second incident light B after passing through the first adjustable mirror 22 and the second adjustable mirror 21 can be completely reflected without transmission loss, thereby improving the utilization rate of the first incident light A and the second incident light B.

[0043] In other embodiments, the first adjustable mirror may also be an adjustable semi-transparent and semi-reflective mirror, and the second adjustable mirror may also be an adjustable semi-transparent and semi-reflective mirror.

[0044] In this embodiment, the first incident light A and the second incident light B are incident to the first position M in different directions, and the exit direction of the second incident light B along the first optical path after it is incident to the first position M is different from the incident direction of the first incident light A at the first position M. The second adjustable mirror 21 is rotated to make the first incident light A incident to the surface of sample 1 along the first optical path at a first incident angle, or to make the second incident light B incident to the surface of sample 1 along the first optical path at a first incident angle; or, the first incident light A incident to the first position M and then along the first optical path... The exit direction of the first incident light A is the same as the incident direction of the second incident light B at the first position M. The second adjustable mirror 21 is moved to cause the first incident light A to be incident on the surface of sample 1 along the first optical path at the first incident angle, or to cause the second incident light to be incident on the surface of sample 1 along the first optical path at the first incident angle. The first adjustable mirror 22 is used to move or rotate to cause the second incident light to be incident on the surface of sample 1 along the second optical path at the second incident angle, or to cause the second incident light to be incident on the first position M and then along the first optical path at the first incident angle on the surface of sample 1. The surface; and / or, the incident directions of the first incident light A and the second incident light B at the second position F are different, and the exit direction of the first incident light A along the second optical path after it is incident at the second position F is different from the incident direction of the second incident light B at the second position F. The first adjustable mirror 22 rotates to make the first incident light A incident on the surface of sample 1 along the second optical path at the second incident angle or to make the second incident light B incident on the surface of sample 1 along the second optical path at the second incident angle; or, the exit direction of the first incident light A along the second optical path after it is incident at the second position F. The direction is the same as the incident direction of the second incident light B at the second position F. The first adjustable mirror 22 is moved to cause the first incident light A to be incident on the surface of sample 1 along the second optical path at the second incident angle, or to cause the second incident light B to be incident on the surface of sample 1 along the second optical path at the second incident angle. The second adjustable mirror 21 is used to move or rotate to cause the first incident light A to be incident on the surface of sample 1 along the first optical path at the first incident angle, or to cause the first incident light A to be incident on the surface of sample 1 along the second optical path at the second incident angle after being incident on the second position F.

[0045] In this embodiment, the optical system further includes one or more light sources.

[0046] Specifically, if the first incident light A and the second incident light B are generated by a single light source, and the light source is used to generate the initial light, the optical system further includes a beam splitter, which is used to split the initial light generated by the light source into the first incident light A and the second incident light B. The optical system may also include one or more guide mirrors, at least one guide mirror for guiding the first incident light A to the second adjustable mirror 21, and at least one guide mirror for guiding the second incident light B to the first adjustable mirror 22.

[0047] If the first incident light A and the second incident light B are generated by different light sources, the optical system may not include the beam splitter. In this embodiment, the optical system further includes: a first directional mirror group 3, located in the first optical path between the second adjustable mirror 21 and the sample 1, for incidenting the first incident light A or the second incident light B onto the surface of the sample at a first incident angle; a second directional mirror group 4, located in the second optical path between the first adjustable mirror 22 and the sample 1, for incidenting the first incident light A or the second incident light B onto the surface of the sample 1 at a second incident angle; and a third directional mirror group 5, which is used to cause the second incident light B to be incident at the first position M, and the third directional mirror group 5 is also used to cause the first incident light A to be incident at the second position F; or, the third directional mirror group 5 is used to adjust the transmission direction of the first incident light A or the second incident light B so that the first incident light A or the second incident light B is transmitted to the surface of the sample 1. The first directional mirror group 3 is used to direct either the first incident light A or the second incident light B onto the surface of the sample 1 at a first incident angle. The first directional mirror group 3 can compensate for the transmission deviation of the first incident light A or the second incident light B, thereby improving the transmission stability of the first incident light A or the second incident light B in the first optical path. The second directional mirror group 4 is used to direct either the first incident light A or the second incident light B onto the surface of the sample 1 at a second incident angle. The second directional mirror group 4 can compensate for the transmission deviation of the first incident light A or the second incident light B, thereby improving the transmission stability of the first incident light A or the second incident light B in the second optical path. The third directional mirror group 5 can also compensate for the transmission deviation of the first incident light A or the second incident light B, thereby improving the transmission stability of the first incident light A or the second incident light B in the optical path. When both the first incident light A and the second incident light B are incident along the first optical path at the first incident angle, the first incident light A and the second incident light B share the first directional mirror group 3. When both the first incident light A and the second incident light B are incident along the second optical path at the second incident angle, the first incident light A and the second incident light B share the second directional mirror group 4.

[0048] In this embodiment, the optical system further includes a first shaping element 6, which is located in the first optical path between the second adjustable mirror 21 and the sample 1. The first shaping element 6 is capable of calibrating the beams of the first incident light A and / or the second incident light B into a standard beam shape that meets the detection requirements.

[0049] In one specific embodiment, the first directional mirror group 3 is located in the first optical path between the first shaping element 6 and the sample 1. The first shaping element 6 is used to transmit the first incident light A or the second incident light B to the first directional mirror group 3, and the first directional mirror group 3 is used to incident the first incident light A or the second incident light B onto the surface of the sample 1 at a first incident angle. The first shaping element 6 can calibrate the beam of the first incident light A and / or the second incident light B to a standard beam shape that meets the detection requirements; at the same time, for the first incident light A and the second incident light B that share the first directional mirror group 3, the first shaping element 6 can eliminate the difference in the parameters of the two types of beams, so that the same set of first directional mirror groups 3 can stably adapt to the transmission requirements of different incident lights, further enhancing the advantage of optical path multiplexing.

[0050] In one embodiment, the first shaping element 6 includes a diffractive optical element and a field lens. Exemplarily, the diffractive optical element is located between the second adjustable mirror 21 and the field lens, and the field lens is located between the diffractive optical element and the first directional mirror group 3. The optical path for the first shaping element 6 to transmit the first incident light A or the second incident light B to the first directional mirror group 3 is as follows: the diffractive optical element transmits the first incident light A or the second incident light B to the field lens, and the field lens transmits the first incident light A or the second incident light B to the first directional mirror group 3.

[0051] In other embodiments, the field lens is located between the second adjustable mirror and the diffractive optical element, and the diffractive optical element is located between the field lens and the first directional mirror group. The optical path for the first shaping element to transmit the first incident light or the second incident light to the first directional mirror group is as follows: the field lens is used to transmit the first incident light or the second incident light to the diffractive optical element, and the diffractive optical element is used to transmit the first incident light A or the second incident light B to the first directional mirror group.

[0052] In this embodiment, the optical system further includes a second shaping element 7, which is located in the second optical path between the first adjustable mirror 22 and the sample 1. The second shaping element 7 can calibrate the beams of the first incident light A and / or the second incident light B to a standard beam shape that meets the detection requirements.

[0053] In one specific embodiment, the second directional mirror group 4 is located in the second optical path between the second shaping element 7 and the sample 1. The second shaping element 7 is used to transmit the first incident light A or the second incident light B to the second directional mirror group 4, and the second directional mirror group 4 is used to incident the first incident light A or the second incident light B onto the surface of the sample 1 at a second incident angle. The second shaping element 7 can calibrate the beams of the first incident light A and / or the second incident light B to a standard beam shape that meets the detection requirements; at the same time, for the first incident light A and the second incident light B that share the second directional mirror group 4, the second shaping element 7 can eliminate the differences in the parameters of the two types of beams, so that the same set of second directional mirror groups 4 can stably adapt to the transmission requirements of different incident lights, further enhancing the advantages of optical path multiplexing.

[0054] In one embodiment, the second shaping element 7 includes a diffractive optical element and a field lens. Exemplarily, the field lens is located between the first adjustable mirror 22 and the diffractive optical element, which is located between the field lens and the second directional mirror group 4. The optical path for the second shaping element 7 to transmit the first incident light A or the second incident light B to the second directional mirror group 4 is as follows: the field lens transmits the first incident light or the second incident light to the diffractive optical element, and the diffractive optical element transmits the first incident light A or the second incident light to the second directional mirror group.

[0055] In other embodiments, the diffractive optical element is located between the first adjustable mirror and the field mirror, and the field mirror is located between the diffractive optical element and the second directional mirror group. The optical path for the second shaping element to transmit the first incident light or the second incident light to the second directional mirror group is as follows: the diffractive optical element is used to transmit the first incident light or the second incident light to the field mirror, and the field mirror is used to transmit the first incident light or the second incident light to the second directional mirror group.

[0056] In one embodiment, the optical system further includes an aperture 8, located between the second adjustable mirror 21 and the first directional mirror group 3, and / or between the first adjustable mirror 22 and the second directional mirror group 4, and / or between the first incident light A and the first adjustable mirror 22, and / or between the second incident light B and the second adjustable mirror 21. The aperture 8 is an entity in the optical system that restricts the incident light. The aperture 8 has a through-hole to filter stray light generated during the transmission of the first incident light A and / or the second incident light B, reducing interference from non-target incident beams on the sample detection signal, thereby improving the signal-to-noise ratio of the detection.

[0057] In other embodiments, the optical system may not have an aperture stop.

[0058] In this embodiment, the optical system further includes one or more detectors (not shown), the optical axes of which are perpendicular to the surface of sample 1 or form an acute angle with the normal to the surface of sample 1. After the first incident light A and / or the second incident light B are incident on the surface of sample 1, they form signal light. The detector is used to receive the first signal light and perform optical processing on the sample according to the signal light.

[0059] The optical system can be used for photolithography or cutting of sample 1, and can also be used for inspection of sample 1. The optical system can also be used in other optical processing of sample 1. In this embodiment, the detector is used to receive signal light to acquire an image of the surface of sample 1, and the detector is used to detect defects on the surface of sample 1 based on the acquired image.

[0060] Figures 1 to 3 A schematic diagram of the optical system provided in the first embodiment of this application.

[0061] A first incident light A is configured to be incident on the surface of sample 1 along a first optical path at a first incident angle; a first adjustable mirror 22 is configured to cause a second incident light B to be incident on the surface of sample 1 along a second optical path at a second incident angle, and the first adjustable mirror 22 is also configured to cause the second incident light B to be incident on the surface of sample 1 along the first optical path at the first incident angle, wherein the first incident angle and the second incident angle are different.

[0062] In this embodiment, the first adjustable mirror 22 is a reflector.

[0063] In this embodiment, the first adjustable mirror 22 is movable, and through the light path, the second incident light B is incident on the surface of the sample 1 at the second incident angle along the second light path, or the second incident light B is incident on the surface of the sample 1 at the first incident angle along the first light path.

[0064] Specifically, such as Figure 1 If the first adjustable mirror 22 moves out of the optical path, the second incident light B is used to bypass the first adjustable mirror 22 and then enter the surface of the sample 1 along the second optical path at the second incident angle; if Figure 2 If the first adjustable mirror 22 moves into the optical path and is at a first preset angle, the second incident light B is also used to be reflected by the first adjustable mirror 22 and then incident along the first optical path at the first incident angle onto the surface of the sample 1. In this embodiment, the incident directions of the first incident light A and the second incident light B at the first position M are different, and the exit direction of the second incident light B along the first optical path after it is incident at the first position M is different from the incident direction of the first incident light A at the first position M. The second adjustable mirror 21 can rotate; specifically, as shown... Figure 1If the second adjustable mirror 21 is at a first angle in the first optical path, the second adjustable mirror 21 is used to cause the first incident light A to be reflected by the second adjustable mirror 21 and then incident on the surface of sample 1 along the first optical path at a first incident angle; Figure 2 If the second adjustable mirror 21 is at the second angle in the first optical path, the second adjustable mirror 21 is used to make the second incident light B incident on the sample 1 surface at the first incident angle after being reflected by the second adjustable mirror 21 and then incident along the first optical path. The second angle is perpendicular to the first angle or has an acute angle between them.

[0065] In this embodiment, the second adjustable mirror 21 is further used to cause the first incident light A to be incident on the second position F, and the first adjustable mirror 22 is further used to cause the first incident light A incident on the second position F to be incident on the surface of the sample 1 along the second optical path at the second incident angle.

[0066] Specifically, the second adjustable mirror 21 can also be moved. If the second adjustable mirror 21 moves out of the first optical path, the first incident light A bypasses the second adjustable mirror 21 and enters the second position F; or, if the second adjustable mirror 21 is at a third angle, the second adjustable mirror 21 is used to allow the first incident light A to enter the second position F. In this embodiment, by moving the second adjustable mirror 21 out of the optical path, the first incident light A bypasses the second adjustable mirror 21 to reach the second position F; in other embodiments, the second adjustable mirror 21 can be rotated to a third angle to move the second adjustable mirror 21 out of the optical path so that the first incident light bypasses the second adjustable mirror 21 to reach the second position F; in other embodiments, such as Figure 4 As shown, by rotating the second adjustable mirror 21 to the third angle, but still within the optical path, the second adjustable mirror 21 causes the first incident light A to reach the second position F by reflecting the first incident light A.

[0067] After the first incident light A is incident at the second position F, its exit direction along the second optical path is the same as the incident direction of the second incident light B at the second position F. The first adjustable mirror 22 is moved to cause the first incident light A to be incident on the sample 1 surface along the second optical path at the second incident angle, or to cause the second incident light B to be incident on the sample surface along the second optical path at the second incident angle. Specifically, as shown... Figure 3 If the first adjustable mirror 22 moves out of the optical path, the second incident light B is incident on the surface of sample 1 along the second optical path at the second incident angle; if the first adjustable mirror 22 moves into the optical path and is at the second preset angle, the first incident light A is reflected by the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at the second incident angle.

[0068] In this embodiment, the first preset angle is different from the second preset angle, and the first adjustable mirror 22 can also be rotated.

[0069] In this embodiment, the second adjustable mirror 21 can both rotate and move. The first adjustable mirror 22 can also rotate and move. Specifically, refer to... Figure 1 The second adjustable mirror 21 is positioned at a first angle in the first optical path (first position M). The first incident light A, after being reflected by the second adjustable mirror 21, is incident on the surface of sample 1 along the first optical path at a first incident angle. The first adjustable mirror 22 moves out of the optical path, and the second incident light B, after bypassing the first adjustable mirror 22, is incident on the surface of sample 1 along the second optical path at a second incident angle. The second adjustable mirror 21 causes the first incident light A to be incident on the surface of sample 1 along the first optical path at a first incident angle, and the first adjustable mirror 22 causes the second incident light B to be incident on the surface of sample 1 along the second optical path at a second incident angle, thus realizing that different incident lights are incident on the surface of sample 1 at different incident angles.

[0070] refer to Figure 2 The first adjustable mirror 22 moves into the second optical path (second position F) at a first preset angle. The angle of the second adjustable mirror 21 in the first optical path can be changed. By rotating and adjusting the angle of the second adjustable mirror 21, the second adjustable mirror 21 is positioned at a second angle in the first optical path. The second incident light B is reflected by the first adjustable mirror 22 and then incident at the first position M. After the second incident light B is incident at the first position M, it is reflected by the second adjustable mirror 21 and then incident on the surface of the sample 1 along the first optical path at a first incident angle. The second adjustable mirror 21 and the first adjustable mirror 22 together cause the second incident light B to be incident on the surface of the sample 1 along the first optical path at a first incident angle. The second incident light B and the first incident light A can share the first optical path.

[0071] Continue to refer to Figure 2 The optical system further includes a third directional mirror group 5, used to direct the second incident light B to the first position M. The second incident light B is used to bypass the first adjustable mirror 22 or, after being reflected by the first adjustable mirror 22, sequentially pass through the third directional mirror group 5, the second adjustable mirror 21, and the first directional mirror group 3 to be incident on the surface of the sample 1 at a first incident angle. The first directional mirror group 3 and the third directional mirror group 5 jointly compensate for the transmission deviation of the second incident light B, thereby improving the transmission stability of the second incident light B.

[0072] refer to Figure 3The second adjustable mirror 21 moves out of the first position M, and the first adjustable mirror 22 is at a second preset angle in the second optical path (second position F). The first incident light A bypasses the second adjustable mirror 21 and enters the second position F. After entering the second position F, the first incident light A is reflected by the first adjustable mirror 22 and then enters the surface of the sample 1. That is, the angle of the first adjustable mirror 22 in the second optical path can be changed. By rotating and adjusting the angle of the first adjustable mirror 22 in the second optical path, it is at the fifth angle. The first adjustable mirror 22 is used to make the first incident light A enter the surface of the sample 1 along the second optical path at the second incident angle after being reflected by the first adjustable mirror 22. The second adjustable mirror 21 and the first adjustable mirror 22 together make the first incident light A enter the surface of the sample 1 along the second optical path at the second incident angle. The second incident light B and the first incident light A can share the second optical path.

[0073] Continue to refer to Figure 3 The optical system further includes a third directional mirror group 5, used to direct the first incident light A to the second position F. The first incident light A is used to bypass the second adjustable mirror 21 or, after being reflected by the second adjustable mirror 21, sequentially pass through the third directional mirror group 5, the first adjustable mirror 22, and the second directional mirror group 4 to be incident on the surface of the sample 1 at a second incident angle. The second directional mirror group 4 and the third directional mirror group 5 jointly compensate for the transmission deviation of the first incident light A, thereby improving the transmission stability of the first incident light A.

[0074] It is understood that if the first adjustable mirror 22 is moved out of the second optical path, the second incident light B is used to bypass the first adjustable mirror 22 and then be incident on the surface of the sample 1 along the second optical path at the second incident angle; if the second adjustable mirror 21 is moved out of the first optical path, the first incident light A is used to bypass the second adjustable mirror 21 and then be incident on the surface of the sample 1 along the first optical path at the first incident angle.

[0075] Figure 4 A schematic diagram of the optical system provided in the second embodiment of this application.

[0076] A first incident light A is configured to be incident on the surface of sample 1 along a first optical path at a first incident angle; a first adjustable mirror 22 is configured to cause a second incident light B to be incident on the surface of sample 1 along a second optical path at a second incident angle, and the first adjustable mirror 22 is also configured to cause the second incident light B to be incident on the surface of sample 1 along the first optical path at the first incident angle, wherein the first incident angle and the second incident angle are different.

[0077] In this embodiment, the first adjustable mirror 22 is rotatable. The first adjustable mirror 22 rotates in the optical path to cause the second incident light B to be incident on the surface of the sample 1 along the second optical path at the second incident angle, or to cause the second incident light B to be incident on the surface of the sample 1 along the first optical path at the first incident angle, or to cause the first incident light A to be incident on the surface of the sample 1 along the second optical path at the second incident angle.

[0078] Specifically, if the incident directions of the first incident light A and the second incident light B are different when they are incident at the second position F, and the exit direction of the first incident light A along the second optical path after it is incident at the second position F is different from the incident direction of the second incident light B at the second position F, the first adjustable mirror 22 is at the fourth angle in the second optical path. The first adjustable mirror 22 is used to make the second incident light B enter the sample 1 surface along the second optical path after being reflected by the first adjustable mirror 22; if the first adjustable mirror 22 is at the fifth angle in the second optical path, the first adjustable mirror 22 is used to make the first incident light A enter the sample 1 surface along the second optical path after it is incident at the second position F, and the fourth angle is perpendicular to the fifth angle or has an acute angle between them; if the first adjustable mirror 22 is at the sixth angle, the first adjustable mirror 22 is used to make the second incident light B enter the first position M.

[0079] In this embodiment, the second adjustable mirror 21 is used to cause the first incident light A to be incident on the surface of the sample 1 along the first optical path at the first incident angle; the second adjustable mirror 21 is also used to cause the second incident light B to be incident on the surface of the sample 1 along the first optical path at the first incident angle; the second adjustable mirror 21 is also used to cause the first incident light A to be incident on the second position F, and the first adjustable mirror 22 is also used to cause the first incident light A incident on the second position F to be incident on the surface of the sample 1 along the second optical path at the second incident angle.

[0080] Specifically, the first incident light A and the second incident light B are incident to the first position M in different directions, and the exit direction of the second incident light B after it is incident to the first position M is different from the incident direction of the first incident light A at the first position M. The second adjustable mirror 21 is rotatable. If the second adjustable mirror 21 is at the first angle in the first optical path, the second adjustable mirror 21 is used to make the first incident light A, after being reflected by the second adjustable mirror 21, incident along the first optical path to the surface of sample 1. If the second adjustable mirror 21 is at the second angle in the first optical path, the second adjustable mirror 21 is used to make the second incident light B, after being incident by the second adjustable mirror 21 and reflected, incident along the first optical path to the surface of sample 1. The second angle is perpendicular to the first angle or has an acute angle between them. If the second adjustable mirror 21 is at the third angle, the second adjustable mirror 21 is used to make the first incident light A incident to the second position F.

[0081] In this embodiment, the second adjustable mirror 21 can only rotate. The first adjustable mirror 22 can only rotate. By controlling the rotation of the second adjustable mirror 21 and the first adjustable mirror 22, the second adjustable mirror 21 is positioned at a first angle in the first optical path, and the first adjustable mirror 22 is positioned at a fourth angle in the second optical path. The first incident light A, after being reflected by the second adjustable mirror 21, enters the surface of sample 1 at a first incident angle, while the second incident light B, after being reflected by the first adjustable mirror 22, enters the surface of sample 1 at a second incident angle. By controlling the first adjustable mirror 22 to be positioned at a sixth angle in the second optical path, and the second adjustable mirror 21 to be positioned at a second angle in the first optical path, the second adjustable mirror 22... Two incident beams B are reflected by the first adjustable mirror 22 and then transmitted to the second adjustable mirror 21. The second adjustable mirror 21 reflects the second incident beam B and then it is incident on the surface of sample 1 along the first optical path at a first incident angle. By controlling the first adjustable mirror 22 to be at a fifth angle in the second optical path and the second adjustable mirror 21 to be at a third angle in the first optical path, the first incident beam A is reflected by the second adjustable mirror 21 and then transmitted to the first adjustable mirror 22. The first adjustable mirror 22 is used to reflect the first incident beam A and then it is incident on the surface of sample 1 along the second optical path at a second incident angle. This achieves the function of "the same incident beam can be switched to different incident angles, different incident beams can share the same optical path, and different incident beams can be incident at different incident angles", while simplifying the optical path structure and reducing costs.

[0082] Figures 5 to 6 A schematic diagram of an optical system provided in the third embodiment of this application.

[0083] A first incident light A is configured to be incident on the surface of sample 1 along a first optical path at a first incident angle; a first adjustable mirror 22 is configured to cause a second incident light B to be incident on the surface of sample 1 along a second optical path at a second incident angle, and the first adjustable mirror is also configured to cause the second incident light to be incident on the surface of sample 1 along the first optical path at the first incident angle, wherein the first incident angle and the second incident angle are different.

[0084] In this embodiment, the first adjustable mirror 22 is movable, so that the second incident light B, after being reflected by the first adjustable mirror 22, is incident on the surface of the sample 1 along the second optical path at the second incident angle, or so that the first incident light A, after being reflected by the first adjustable mirror 22, is incident on the surface of the sample along the first optical path at the first incident angle. Specifically, the first incident light A, after being reflected by the first adjustable mirror 22, reaches the first position M, and after passing through the first position M, is incident on the surface of the sample 1 along the first optical path at the first incident angle.

[0085] The optical system further includes a second adjustable mirror 21, used to direct the first incident light A along the second optical path to the surface of the sample at a second incident angle. Specifically, the second adjustable mirror 21 is used to direct the first incident light A to the second position F, and the first adjustable mirror 22 is also used to direct the first incident light A incident at the second position F along the second optical path to the surface of the sample 1 at a second incident angle.

[0086] In this embodiment, the second adjustable mirror 21 is movable, so that the first incident light A, after being reflected by the second adjustable mirror 21, is incident on the surface of the sample along the first optical path at the first incident angle, or so that the first incident light A, after passing the second position F, is incident on the surface of the sample along the second optical path at the second incident angle. Specifically, the first incident light A, after passing the second position F, reaches the first position M, and after passing the first position M, is incident on the surface of the sample 1 along the first optical path at the first incident angle.

[0087] In this embodiment, after the first incident light A is incident at the second position F, its exit direction along the second optical path is the same as the incident direction of the second incident light B at the second position F. The first adjustable mirror 22 is movable, and the incident directions of the first incident light A and the second incident light B are the same but staggered when incident on the first adjustable mirror 22. The first adjustable mirror 22 switches the incident light between the first incident light A and the second incident light B so that the first incident light A is incident on the sample surface along the second optical path at a second incident angle, or so that the second incident light B is incident on the sample surface along the second optical path at a second incident angle. Specifically, as shown... Figure 5 The first adjustable mirror 22 is located in the first incident light path. The first adjustable mirror 22 is used to ensure that the first incident light A, after being reflected by the first adjustable mirror 22, is incident on the surface of sample 1 along the second light path at a second incident angle; for example... Figure 6 The first adjustable mirror 22 is located in the second incident light path. The first adjustable mirror 22 is used to ensure that the second incident light B, after being reflected by the first adjustable mirror 22, is incident on the sample surface along the second light path at a second incident angle. In this embodiment, the second adjustable mirror 21 is movable, such as... Figure 5 The first incident light A is used to bypass the second adjustable mirror 21 and then be transmitted to the first adjustable mirror 22. The first adjustable mirror 22 is used to ensure that the first incident light A, after being reflected by the first adjustable mirror 22, is incident on the surface of sample 1 along the second optical path at the second incident angle; such as Figure 6 The second incident light B is used to bypass the second adjustable mirror 21 and then be transmitted to the first adjustable mirror 22. The first adjustable mirror 22 is used to make the second incident light B reflect off the first adjustable mirror 22 and then be incident on the sample surface along the second optical path at the second incident angle.

[0088] In this embodiment, after the first incident light A is incident at the first position M, its exit direction along the first optical path is the same as the incident direction of the second incident light B at the first position M. The second adjustable mirror 21 is movable, and the incident directions of the first incident light A and the second incident light B are the same but staggered when incident on the second adjustable mirror 21. The second adjustable mirror 21 switches the incident light between the first incident light A and the second incident light B so that the first incident light A is incident on the surface of sample 1 along the first optical path at the first incident angle, or so that the second incident light B is incident on the surface of sample 1 along the first optical path at the first incident angle.

[0089] Specifically, such as Figure 5 The second adjustable mirror 21 is located in the second incident light path. The second adjustable mirror 21 is used to ensure that the second incident light B, after being reflected by the second adjustable mirror 21, is incident on the sample surface along the first light path at a first incident angle; for example... Figure 6 The second adjustable mirror 21 is located in the first incident light path. The second adjustable mirror 21 is used to make the first incident light A reflect off the second adjustable mirror 21 and then be incident on the sample surface along the first light path at the first incident angle.

[0090] In this embodiment, if the first adjustable mirror 22 is in the first state and the second adjustable mirror 21 is in the second state, the second incident light B is incident on the surface of sample 1 along the second optical path at the second incident angle, and the first incident light A is incident on the surface of sample 1 along the first optical path at the first incident angle. If the first adjustable mirror 22 is in the third state and the second adjustable mirror 21 is in the fourth state, the first incident light A is incident on the surface of sample 1 along the second optical path at the second incident angle, and the second incident light B is incident on the surface of sample 1 along the first optical path at the first incident angle. This achieves the simultaneous incident of different incident lights on the surface of sample 1 at different incident angles.

[0091] In this embodiment, the second adjustable mirror 21 is only movable. The first adjustable mirror 22 is only movable. Specifically, refer to... Figure 5 The third state is that the first adjustable mirror 22 is located in the optical path of the first incident light A, and the fourth state is that the second adjustable mirror 21 is located in the optical path of the second incident light B. The first incident light A is reflected by the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at a second incident angle, and the second incident light B is reflected by the second adjustable mirror 21 and then incident on the surface of sample 1 along the first optical path at a first incident angle; Reference Figure 6 In the first state, the first adjustable mirror 22 is located in the optical path of the second incident light B, and in the second state, the second adjustable mirror 21 is located in the optical path of the first incident light A. After being reflected by the first adjustable mirror 22, the second incident light B is incident on the surface of sample 1 along the second optical path at the second incident angle, and the first incident light A is incident on the surface of sample 1 along the first optical path at the first incident angle after being reflected by the second adjustable mirror 21.

[0092] Further, refer to Figures 5 to 6In this embodiment, the optical system further includes a third directional mirror group 5, located between the first adjustable mirror 22 and the second directional mirror group 4. For example, the third directional mirror group 5 is located between the first adjustable mirror 22 and the second shaping element 7. If the first adjustable mirror 22 is in a first state and the second adjustable mirror 21 is in a second state, the second incident light B is used to bypass the first adjustable mirror 22 or, after reflection by the first adjustable mirror 22, sequentially pass through the third directional mirror group 5, the second shaping element 7, and the second directional mirror group 4 before incident on the surface of sample 1 at a second incident angle. The first incident light A is used to be reflected by the second adjustable mirror 21, sequentially pass through the first shaping element 6 and the first directional mirror group 3 before incident on the surface of sample 1 at a first incident angle. The third directional mirror group 5 and the second directional mirror group 4 jointly compensate for the transmission deviation of the second incident light B, improving the transmission stability of the second incident light B. The first directional mirror group 3 can compensate for the transmission deviation of the first incident light A, improving the transmission stability of the first incident light A. Transmission stability; if the first adjustable mirror 22 is in the third state and the second adjustable mirror 21 is in the fourth state, the first incident light A is reflected by the first adjustable mirror 22 and then passes through the third directional mirror group 5, the second shaping element 7 and the second directional mirror group 4 in sequence before being incident on the surface of the sample 1 at the second incident angle. The second incident light B is reflected by the second adjustable mirror 21 and then passes through the first shaping element 6 and the first directional mirror group 3 in sequence before being incident on the surface of the sample 1 at the first incident angle. The third directional mirror group 5 and the second directional mirror group 4 jointly compensate for the transmission deviation of the first incident light A, thereby improving the transmission stability of the first incident light A. The first directional mirror group 3 can compensate for the transmission deviation of the second incident light B, thereby improving the transmission stability of the second incident light B.

[0093] Figures 7 to 8 A schematic diagram of the optical system provided in the fourth embodiment of this application.

[0094] This embodiment and Figure 6 and Figure 5 The similarities between the embodiments shown will not be repeated, while the differences include: A first incident light A is configured to be incident on the surface of sample 1 along a first optical path at a first incident angle; a first adjustable mirror 22 is configured to cause a second incident light B to be incident on the surface of sample 1 along a second optical path at a second incident angle, and the first adjustable mirror 22 is also configured to cause the second incident light B to be incident on the surface of sample 1 along the first optical path at the first incident angle, wherein the first incident angle and the second incident angle are different.

[0095] In this embodiment, the first adjustable mirror 22 is movable. By moving the first adjustable mirror 22, the second incident light B is reflected by the first adjustable mirror 22 and then incident on the surface of the sample along the second light path at the second incident angle. Alternatively, the second incident light B is used to bypass the first adjustable mirror 22 and then incident on the surface of the sample along the second light path at the second incident angle.

[0096] In this embodiment, the first incident light A and the second incident light B are incident to the second position F in different directions. The first incident light A is incident to the second position F and then exits along the second optical path in the same direction as the second incident light B at the second position F. The first adjustable mirror 22 is movable. The first adjustable mirror 22 allows the first incident light A to be incident on the sample surface along the second optical path at a second incident angle or the second incident light B to be incident on the sample surface along the second optical path at a second incident angle by entering and exiting the optical path.

[0097] Specifically, such as Figure 7 The first adjustable mirror 22 is located at the second position F. The first adjustable mirror 22 is used to ensure that the first incident light A, after being reflected by the first adjustable mirror 22, is incident on the surface of sample 1 along the second optical path at the second incident angle; for example... Figure 8 The first adjustable mirror 22 is moved out of the second position F. The first adjustable mirror 22 is used to allow the second incident light to bypass the first adjustable mirror 22 and then be incident on the sample surface along the second optical path at the second incident angle. In this embodiment, the second adjustable mirror 21 is movable, such as... Figure 7 The second adjustable mirror 21 moves out of the first position M, and the first incident light A is used to bypass the second adjustable mirror 21 and then be transmitted to the first adjustable mirror 22. The first adjustable mirror 22 is used to make the first incident light A reflect off the first adjustable mirror 22 and then be incident on the surface of sample 1 along the second optical path at the second incident angle; Figure 8 The second adjustable mirror 21 is located at the first position M. The second incident light B is used to bypass the second adjustable mirror 21 and then be transmitted. During the transmission process, the second incident light bypasses the first adjustable mirror 22 and then enters the sample surface along the second optical path at the second incident angle.

[0098] In this embodiment, after the first incident light A is incident to the first position M, its exit direction along the first optical path is the same as the incident direction of the second incident light B at the first position M. The second adjustable mirror 21 is movable, and the first incident light A and the second incident light B are incident to the second adjustable mirror 21 in the same but staggered direction. The second adjustable mirror 21, through the entry and exit optical paths, enables the first incident light A to be incident on the surface of sample 1 along the first optical path at a first incident angle, or enables the second incident light B to be incident on the surface of sample 1 along the first optical path at a first incident angle.

[0099] Specifically, such as Figure 7The second adjustable mirror 21 is moved out of the first position M. The second adjustable mirror 21 is used to cause the second incident light B to be reflected by the second adjustable mirror 21 and then incident on the sample surface along the first optical path at the first incident angle; such as Figure 8 The second adjustable mirror 21 is located at the first position M. The second adjustable mirror 21 is used to make the first incident light A reflect off the second adjustable mirror 21 and then be incident on the sample surface along the first light path at the first incident angle.

[0100] In this embodiment, if the first adjustable mirror 22 is in the first state and the second adjustable mirror 21 is in the second state, the second incident light B is incident on the surface of sample 1 along the second optical path at the second incident angle, and the first incident light A is incident on the surface of sample 1 along the first optical path at the first incident angle. If the first adjustable mirror 22 is in the third state and the second adjustable mirror 21 is in the fourth state, the first incident light A is incident on the surface of sample 1 along the second optical path at the second incident angle, and the second incident light B is incident on the surface of sample 1 along the first optical path at the first incident angle. This achieves the simultaneous incident of different incident lights on the surface of sample 1 at different incident angles.

[0101] In this embodiment, the second adjustable mirror 21 is only movable. The first adjustable mirror 22 is only movable. Specifically, refer to... Figure 7 The third state is that the first adjustable mirror 22 is located in the second position F, and the fourth state is that the second adjustable mirror 21 is moved out of the first position M, the first incident light A bypasses the second adjustable mirror 21 and then enters the surface of sample 1 along the second optical path at the second incident angle, and the second incident light B is reflected by the second adjustable mirror 21 and then enters the surface of sample 1 along the first optical path at the first incident angle; Reference Figure 8 The first state is when the first adjustable mirror 22 moves out of the second position F, and the second state is when the second adjustable mirror 21 is located in the first position M. The second incident light B bypasses the first adjustable mirror 22 and then enters the sample 1 surface along the second light path at the second incident angle. The first incident light A is reflected by the second adjustable mirror 21 and then enters the sample 1 surface along the first light path at the first incident angle.

[0102] The optical system also includes one or a combination of a first reflecting element (not shown) and a second reflecting element 9. In this embodiment, reference is made to... Figure 7 and Figure 8 The optical system includes a second reflecting element 9. If the first adjustable mirror 22 moves out of the second position F, the second incident light B, after being incident on the second reflecting element 9, is reflected by the second reflecting element 9 and then incident on the surface of the sample 1 along the second optical path at a second incident angle. In other embodiments, the optical system further includes a first reflecting element. If the second adjustable mirror 21 moves out of the first position M, the second incident light B, after being incident on the first reflecting element, is reflected by the first reflecting element and then incident on the sample surface along the first optical path at a first incident angle.

[0103] Further, refer to Figures 7 to 8 In this embodiment, the optical system further includes a third directional mirror group 5, located between the first adjustable mirror 22 and the second directional mirror group 4. For example, the third directional mirror group 5 is located between the first adjustable mirror 22 and the second shaping element 7. If the first adjustable mirror 22 is in a first state and the second adjustable mirror 21 is in a second state, the second incident light B, after being reflected by the second reflecting element 9, bypasses the first adjustable mirror 22 and then sequentially passes through the third directional mirror group 5, the second shaping element 7, and the second directional mirror group 4 before incident on the surface of sample 1 at a second incident angle. The first incident light A, after being reflected by the second adjustable mirror 21, sequentially passes through the first shaping element 6 and the first directional mirror group 3 before incident on the surface of sample 1 at a first incident angle. The third directional mirror group 5 and the second directional mirror group 4 jointly compensate for the transmission deviation of the second incident light B, improving the transmission stability of the second incident light B. The first directional mirror group 3 can compensate for the transmission deviation of the first incident light A, improving the transmission stability of the first incident light A. Transmission stability; if the first adjustable mirror 22 is in the third state and the second adjustable mirror 21 is in the fourth state, the first incident light A is reflected by the first adjustable mirror 22 and then passes through the third directional mirror group 5, the second shaping element 7 and the second directional mirror group 4 in sequence before being incident on the surface of the sample 1 at the second incident angle. The second incident light B is reflected by the second adjustable mirror 21 and then passes through the first shaping element 6 and the first directional mirror group 3 in sequence before being incident on the surface of the sample 1 at the first incident angle. The third directional mirror group 5 and the second directional mirror group 4 jointly compensate for the transmission deviation of the first incident light A, thereby improving the transmission stability of the first incident light A. The first directional mirror group 3 can compensate for the transmission deviation of the second incident light B, thereby improving the transmission stability of the second incident light B.

[0104] This embodiment also provides a method for operating the optical system provided in the foregoing embodiment, including: a first incident light A is incident on the surface of sample 1 along a first optical path at a first incident angle; a second incident light B is incident on the surface of sample 1 along a second optical path at a second incident angle through the first adjustable mirror 22, and the second incident light B is incident on the surface of sample 1 along the first optical path at a first incident angle through the first adjustable mirror 22.

[0105] In this embodiment, the second incident light B being incident on the surface of sample 1 along the second optical path at the second incident angle via the first adjustable mirror 22 includes: the second incident light B passing through the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at the second incident angle, or the second incident light B bypassing the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at the second incident angle; the second incident light B being incident on the surface of sample 1 along the first optical path at the first incident angle via the first adjustable mirror 22 includes: the second incident light B passing through the first adjustable mirror 22 and then incident on the surface of sample 1 along the first optical path at the first incident angle, or the second incident light B bypassing the first adjustable mirror 22 and then incident on the surface of sample 1 along the first optical path at the first incident angle.

[0106] In this embodiment, the optical system further includes: a second adjustable mirror 21; the second adjustable mirror 21 causes the first incident light A to be incident on the surface of the sample along the first optical path at a first incident angle, and the second incident light B to be incident on the surface of the sample along the first optical path at a first incident angle.

[0107] In this embodiment, the second adjustable mirror is positioned at a first position M in the first optical path, and the first adjustable mirror is positioned at a second position F in the second optical path.

[0108] Specifically, the method of directing the second incident light B along the first optical path to the surface of the sample 1 at the first incident angle via the first adjustable mirror 22 includes: after directing the second incident light to the first position M via the first adjustable mirror 22, the second incident light B along the first optical path to the surface of the sample 1 at the first incident angle; the method of directing the first incident light along the second optical path to the surface of the sample 1 via the second adjustable mirror 21 includes: after directing the first incident light to the second position F via the second adjustable mirror 21, the first incident light A along the second optical path to the surface of the sample at the second incident angle.

[0109] In one embodiment, if the incident directions of the first incident light A and the second incident light B are different when they are incident at the first position M, and the exit direction of the second incident light B along the first optical path after it is incident at the first position M is different from the incident direction of the first incident light A at the first position M, the second adjustable mirror 21 can be rotated; directing the first incident light A along the first optical path to the surface of sample 1 at a first incident angle via the second adjustable mirror 21 includes: moving the second adjustable mirror 21 into the first optical path and placing it at a first angle, and then directing the first incident light A along the first optical path to the surface of sample 1 at a first incident angle after reflection by the second adjustable mirror 21; directing the second incident light A along the first optical path to the surface of sample 1 at a first incident angle via ... The incident light along the first optical path at a first incident angle to the surface of sample 1 includes: moving the second adjustable mirror 21 into the first optical path and placing it at a second angle, and the second incident light B being incident on the second adjustable mirror 21 and reflected before being incident on the sample surface along the first optical path at the first incident angle; the incident light A being incident on the surface of sample 1 along the second optical path at the second incident angle via the second adjustable mirror 21 includes: placing the second adjustable mirror 21 at a third angle in the first optical path, the first incident light A being reflected by the second adjustable mirror 21 and incident at a second position F, and then the first incident light A being incident on the surface of sample 1 along the second optical path at the second incident angle; and / or, If the incident directions of the first incident light A and the second incident light B are different when they are incident at the second position F, and the exit direction of the first incident light A along the second optical path after it is incident at the second position F is different from the incident direction of the second incident light B at the second position F, the first adjustable mirror 22 can be rotated; the second incident light B is directed to the surface of sample 1 along the second optical path at a second incident angle by the first adjustable mirror 22, including: moving the first adjustable mirror 22 into the second optical path and placing it at a fourth angle, the second incident light being reflected by the first adjustable mirror 22 and then incident on the surface of sample 1 along the second optical path at a second incident angle; the first incident light A is directed to the surface of sample 1 along the second optical path at a second incident angle by the first adjustable mirror 22. The second incident light A is incident on the surface of sample 1 at a second incident angle via the first adjustable mirror 22, which is moved into the second optical path and positioned at a fifth angle. The first incident light A is incident on the surface of sample 1 at a second incident angle after being reflected by the first adjustable mirror 22. The second incident light B is incident on the surface of sample 1 at the first incident angle via the first adjustable mirror 22, which is moved into the second optical path at a first incident angle via the first adjustable mirror 22, which is positioned at a sixth angle in the second optical path. The second incident light B is incident on the surface of sample 1 at a first position M after being reflected by the first adjustable mirror 22. After that, the second incident light B is incident on the surface of sample 1 at a first incident angle via the first optical path.

[0110] In another embodiment, if the incident directions of the first incident light A and the second incident light B are different when they are incident on the first position M, and the exit direction of the second incident light B along the first optical path after it is incident on the first position M is different from the incident direction of the first incident light A at the first position M, the second adjustable mirror 21 can also be moved. Making the first incident light A along the second optical path and incident on the surface of the sample 1 at the second incident angle via the second adjustable mirror 21 includes: moving the second adjustable mirror 21 out of the first optical path, the first incident light A bypassing the second adjustable mirror 21 and incident on the second position F, and then the first incident light A along the second optical path and incident on the surface of the sample 1 at the second incident angle; or, making the first incident light A along the first optical path and incident on the surface of the sample 1 at the first incident angle via the second adjustable mirror 21 includes: moving the second adjustable mirror 21 out of the first optical path, the first incident light A bypassing the second adjustable mirror 21 and then incident on the surface of the sample 1 along the first optical path at the first incident angle; and / or, If the incident directions of the first incident light A and the second incident light B are different when they are incident at the second position F, and the exit direction of the first incident light A along the second optical path after it is incident at the second position F is different from the incident direction of the second incident light B at the second position F, the first adjustable mirror 22 can also be moved. Making the second incident light B incident along the first optical path at the first incident angle to the surface of the sample 1 via the first adjustable mirror 22 includes: moving the first adjustable mirror 22 out of the second optical path, the second incident light bypassing the first adjustable mirror 22 and incident at the first position M, and then the second incident light B incident along the first optical path at the first incident angle to the surface of the sample 1; or, making the second incident light B incident along the second optical path at the second incident angle to the surface of the sample 1 via the first adjustable mirror 22 includes: moving the first adjustable mirror 22 out of the second optical path, the second incident light B bypassing the first adjustable mirror 22 and then incident along the second optical path at the second incident angle to the surface of the sample.

[0111] In another embodiment, if the exit direction of the first incident light A after it is incident on the first position M is the same as the incident direction of the second incident light B after it is incident on the first position M; and / or, the exit direction of the first incident light A after it is incident on the second position F is the same as the incident direction of the second incident light B after it is incident on the second position F; the first adjustable mirror 22 is in a first state, and the second adjustable mirror 21 is in a second state, so that the first incident light A is incident on the surface of the sample 1 along the first optical path at a first incident angle through the second adjustable mirror 21, and the second incident light B is incident on the surface of the sample 1 along the second optical path at a second incident angle through the first adjustable mirror 22; the first adjustable mirror 22 is in a third state, and the second adjustable mirror 21 is in a fourth state, so that the second incident light B is incident on the surface of the sample 1 along the first optical path at a first incident angle through the second adjustable mirror 21, and the first incident light A is incident on the surface of the sample 1 along the second optical path at a second incident angle through the first adjustable mirror 22.

[0112] The first incident light A and the second incident light B are incident on the second adjustable mirror 21 in the same but staggered direction, and / or the first incident light A and the second incident light B are incident on the first adjustable mirror 22 in the same but staggered direction; the first state is that the first adjustable mirror 22 is located in the optical path of the second incident light B, and the second state is that the second adjustable mirror 21 is located in the optical path of the first incident light A, and the second incident light B, after being reflected by the first adjustable mirror 22, is incident on the surface of sample 1 along the second optical path at a second incident angle. The first incident light A is reflected by the second adjustable mirror 21 and then incident on the sample surface along the first optical path at the first incident angle; the third state is that the first adjustable mirror 22 is located in the optical path of the first incident light A, and the fourth state is that the second adjustable mirror 21 is located in the optical path of the second incident light B, the first incident light A is reflected by the first adjustable mirror 22 and then incident on the sample surface along the second optical path at the second incident angle, and the second incident light B is reflected by the second adjustable mirror 21 and then incident on the sample surface along the first optical path at the first incident angle.

[0113] The first incident light A and the second incident light B have different incident directions when incident to the first position M. The exit direction of the first incident light A after incident to the first position M is the same as the incident direction of the second incident light B when incident to the first position M. Alternatively, the first incident light A and the second incident light B have different incident directions when incident to the second position F. The exit direction of the first incident light A after incident to the second position F is the same as the incident direction of the second incident light B when incident to the second position F. The first state is that the first adjustable mirror 22 has moved out of the second position F. The second state is that the second adjustable mirror 21 is located at the first position M. Light B bypasses the first adjustable mirror 22 and is incident on the surface of sample 1 along the second optical path at the second incident angle. The first incident light A is reflected by the second adjustable mirror 21 and is incident on the surface of sample 1 along the first optical path at the first incident angle. The third state is when the first adjustable mirror 22 is located in the second position F. The fourth state is when the second adjustable mirror 21 is moved out of the first position M. The first incident light A bypasses the second adjustable mirror 21 and passes through the first adjustable mirror 22 and is incident on the surface of sample 1 along the second optical path at the second incident angle. The second incident light B is reflected by the second adjustable mirror 21 and is incident on the surface of sample 1 along the first optical path at the first incident angle.

[0114] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An optical system, characterized in that, include: The first incident light is configured to be incident on the surface of the sample along the first optical path at a first incident angle; A first adjustable mirror is used to cause a second incident light to be incident on the surface of the sample along a second optical path at a second incident angle. The first adjustable mirror is also used to cause the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle. The first incident angle and the second incident angle are different. It also includes: a second adjustable mirror, the second adjustable mirror being used to cause the first incident light to be incident on the surface of the sample along the first optical path at the first incident angle, the second adjustable mirror being further used to cause the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle.

2. The optical system according to claim 1, characterized in that, The second incident light is used to be reflected by the first adjustable mirror and then incident on the surface of the sample along the second optical path at the second incident angle; or, the second incident light is used to bypass the first adjustable mirror and then incident on the surface of the sample along the second optical path at the second incident angle; the second incident light is also used to be reflected by the first adjustable mirror and then incident on the surface of the sample along the first optical path at the first incident angle; or, the second incident light is also used to bypass the first adjustable mirror and then incident on the surface of the sample along the first optical path at the first incident angle.

3. The optical system according to claim 1, characterized in that, The first adjustable mirror is positioned in the second optical path as a second position, the second adjustable mirror is positioned in the first optical path as a first position, the second adjustable mirror is also used to cause the first incident light to be incident on the second position, and the first adjustable mirror is also used to cause the first incident light incident on the second position to be incident on the surface of the sample along the second optical path at a second incident angle. The first adjustable mirror is specifically used to cause the second incident light to be incident on the first position, and then the second incident light to be incident on the surface of the sample along the first optical path at a first incident angle; the second adjustable mirror is specifically used to cause the first incident light to be incident on the second position, and then the first incident light to be incident on the surface of the sample along the second optical path at a second incident angle.

4. The optical system according to any one of claims 1 to 3, characterized in that, Both the first adjustable mirror and the second adjustable mirror are reflectors; the first adjustable mirror is positioned at a second position in the second optical path, and the second adjustable mirror is positioned at a first position in the first optical path. The first incident light and the second incident light have different incident directions when they are incident on the first position, and the exit direction of the second incident light along the first optical path after it is incident on the first position is different from the incident direction of the first incident light at the first position. The second adjustable mirror rotates to make the first incident light or the second incident light be incident on the sample surface along the first optical path at the first incident angle. Alternatively, the exit direction of the first incident light along the first optical path after it is incident on the first position is the same as the incident direction of the second incident light at the first position. The second adjustable mirror moves to make the first incident light or the second incident light be incident on the sample surface along the first optical path at the first incident angle. The first adjustable mirror is used to move or rotate to cause the second incident light to be incident on the surface of the sample along the second optical path at the second incident angle, or to cause the second incident light to be incident on the first position and then along the first optical path at the first incident angle to be incident on the surface of the sample. And / or, The first incident light and the second incident light have different incident directions when they are incident on the second position, and the exit direction of the first incident light along the second optical path after it is incident on the second position is different from the incident direction of the second incident light at the second position. The first adjustable mirror is rotated to make the first incident light incident on the sample surface along the second optical path at the second incident angle or to make the second incident light incident on the sample surface along the second optical path at the second incident angle; or, the exit direction of the first incident light along the second optical path after it is incident on the second position is the same as the incident direction of the second incident light at the second position. The first adjustable mirror is moved to make the first incident light incident on the sample surface along the second optical path at the second incident angle or to make the second incident light incident on the sample surface along the second optical path at the second incident angle. The second adjustable mirror is used to move or rotate to cause the first incident light to be incident on the surface of the sample along the first optical path at a first incident angle, or to cause the first incident light to be incident on the surface of the sample along the second optical path at a second incident angle after being incident on the second position.

5. The optical system according to claim 4, characterized in that, If the first adjustable mirror is in the first state and the second adjustable mirror is in the second state, the second incident light is incident on the sample surface along the second optical path at the second incident angle, and the first incident light is incident on the sample surface along the first optical path at the first incident angle. If the first adjustable mirror is in the third state and the second adjustable mirror is in the fourth state, the first incident light is incident on the sample surface along the second optical path at the second incident angle, and the second incident light is incident on the sample surface along the first optical path at the first incident angle.

6. The optical system according to claim 4, characterized in that, If the incident directions of the first incident light and the second incident light are different when they are incident on the first position, and the exit direction of the second incident light along the first optical path after it is incident on the first position is different from the incident direction of the first incident light at the first position, the second adjustable mirror can be rotated. If the second adjustable mirror is at a first angle in the first optical path, the second adjustable mirror is used to cause the first incident light to be reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at a first incident angle; if the second adjustable mirror is at a second angle in the first optical path, the second adjustable mirror is used to cause the second incident light to be incident on the sample surface along the first optical path at a first incident angle after being reflected by the second adjustable mirror, wherein the second angle is perpendicular to the first angle or has an acute angle between them; The second adjustable mirror can also be moved. If the second adjustable mirror moves out of the first optical path, the first incident light bypasses the second adjustable mirror and enters the second position; or, if the second adjustable mirror is at a third angle, the second adjustable mirror is used to allow the first incident light to enter the second position; and / or, If the first incident light and the second incident light are incident in different directions when they reach the second position, and the exit direction of the first incident light along the second optical path after it reaches the second position is different from the incident direction of the second incident light at the second position, the first adjustable mirror can be rotated. If the first adjustable mirror is at the fourth angle in the second optical path, the first adjustable mirror is used to cause the second incident light to be reflected by the first adjustable mirror and then incident on the sample surface along the second optical path at the second incident angle; if the first adjustable mirror is at the fifth angle in the second optical path, the first adjustable mirror is used to cause the first incident light to be incident on the sample surface by the first adjustable mirror and then incident on the second optical path at the second incident angle, wherein the fourth angle is perpendicular to the fifth angle or has an acute angle between them; The first adjustable mirror can also be moved. If the first adjustable mirror moves out of the second optical path, the second incident light bypasses the first adjustable mirror and enters the first position; or, if the first adjustable mirror is at the sixth angle, the first adjustable mirror is used to make the second incident light enter the first position.

7. The optical system according to claim 5, characterized in that, The first incident light and the second incident light have different incident directions when incident on the first position. After the first incident light is incident on the first position, the exit direction along the first optical path is the same as the incident direction of the second incident light when incident on the first position. The second adjustable mirror causes the first incident light to be incident on the sample surface along the first optical path at a first incident angle or causes the second incident light to be incident on the sample surface along the first optical path at a first incident angle by entering and exiting the optical path. Alternatively, the first incident light and the second incident light are incident on the second adjustable mirror in the same but staggered directions. The second adjustable mirror causes the first incident light to be incident on the sample surface along the first optical path at a first incident angle or causes the second incident light to be incident on the sample surface along the first optical path at a first incident angle by switching the incident directions of the first incident light and the second incident light. The first adjustable mirror is used to move so that the first incident light is incident on the sample surface along the second optical path at the second incident angle, or to cause the second incident light to be incident on the sample surface along the second optical path at the second incident angle. And / or, The first incident light and the second incident light have different incident directions when they are incident on the second position. After the first incident light is incident on the second position, its exit direction along the second optical path is the same as the incident direction of the second incident light when it is incident on the second position. The first adjustable mirror causes the first incident light to be incident on the sample surface along the second optical path at a second incident angle or causes the second incident light to be incident on the sample surface along the second optical path at a second incident angle by entering and exiting the optical path. Alternatively, the first incident light and the second incident light are incident on the first adjustable mirror in the same but staggered directions. The first adjustable mirror causes the first incident light to be incident on the sample surface along the second optical path at a second incident angle or causes the second incident light to be incident on the sample surface along the second optical path at a second incident angle by switching the incident directions of the first incident light and the second incident light. The second adjustable mirror is used to move so that the first incident light is incident on the sample surface along the first optical path at the first incident angle, or to cause the second incident light to be incident on the sample surface along the first optical path at the first incident angle.

8. The optical system according to claim 7, characterized in that, The first incident light and the second incident light are incident on the second adjustable mirror in the same but staggered directions, and / or the first incident light and the second incident light are incident on the first adjustable mirror in the same but staggered directions. The first state is when the first adjustable mirror is located in the second incident light path, and the second state is when the second adjustable mirror is located in the first incident light path; The second incident light is reflected by the first adjustable mirror and then incident on the sample surface along the second optical path at the second incident angle, and the first incident light is reflected by the second adjustable mirror and then incident on the sample surface along the first optical path at the first incident angle. The third state is that the first adjustable mirror is located in the first incident light path, and the fourth state is that the second adjustable mirror is located in the second incident light path. The first incident light is reflected by the first adjustable mirror and then incident on the sample surface along the second light path at the second incident angle, and the second incident light is reflected by the second adjustable mirror and then incident on the sample surface along the first light path at the first incident angle.

9. The optical system according to claim 7, characterized in that, The first incident light and the second incident light have different incident directions when they are incident on the first position. The exit direction of the first incident light along the first optical path after it is incident on the first position is the same as the incident direction of the second incident light when it is incident on the first position. Or, the first incident light and the second incident light have different incident directions when they are incident on the second position. The exit direction of the first incident light along the second optical path after it is incident on the second position is the same as the incident direction of the second incident light when it is incident on the second position. The first state is when the first adjustable mirror moves out of the second position, and the second state is when the second adjustable mirror is in the first position. The second incident light bypasses the first adjustable mirror and then enters the sample surface along the second light path at the second incident angle. The first incident light is reflected by the second adjustable mirror and then enters the sample surface along the first light path at the first incident angle. The third state is when the first adjustable mirror is in the second position, and the fourth state is when the second adjustable mirror moves out of the first position, the first incident light bypasses the second adjustable mirror and then enters the sample surface along the second light path at the second incident angle, and the second incident light is reflected by the second adjustable mirror and then enters the sample surface along the first light path at the first incident angle.

10. The optical system according to claim 9, characterized in that, The optical system further includes one or a combination of a first reflective element and a second reflective element. If the first adjustable mirror moves out of the second position, the second incident light is incident on the second reflective element and then reflected by the second reflective element before being incident on the sample surface along the second optical path at a second incident angle. If the second adjustable mirror moves out of the first position, the second incident light is incident on the first reflective element and then reflected by the first reflective element before being incident on the sample surface along the first optical path at a first incident angle.

11. The optical system according to any one of claims 1 to 3, characterized in that, The first adjustable mirror is positioned at a second position in the second optical path, and the second adjustable mirror is positioned at a first position in the first optical path. The system further includes: a first directional mirror group located in the first optical path between the second adjustable mirror and the sample, used to direct the first incident light or the second incident light onto the surface of the sample at a first incident angle; a second directional mirror group located in the second optical path between the first adjustable mirror and the sample, used to direct the first incident light or the second incident light onto the surface of the sample at a second incident angle; and a third directional mirror group, used to direct the second incident light to the first position, and also used to direct the first incident light to the second position; or, the third directional mirror group is used to adjust the transmission direction of the first incident light or the second incident light so that the first incident light or the second incident light is transmitted to the surface of the sample.

12. The optical system according to any one of claims 1 to 3, characterized in that, Also includes: A first shaping element is located in a first optical path between the second adjustable mirror and the sample; The second shaping element is located in the second optical path between the first adjustable mirror and the sample.

13. The optical system according to claim 1, characterized in that, The optical system also includes one or more detectors, the optical axes of which are perpendicular to the sample surface or have an acute angle with the sample surface normal.

14. A method of operating an optical system according to any one of claims 1 to 13, characterized in that, include: The first incident light is incident on the surface of the sample along the first optical path at the first incident angle; The second incident light is incident on the surface of the sample along the second optical path at the second incident angle through the first adjustable mirror, and the second incident light is incident on the surface of the sample along the first optical path at the first incident angle through the first adjustable mirror. The first incident angle and the second incident angle are different.

15. The method of operating the optical system according to claim 14, characterized in that, Also includes: Second adjustable lens; The second adjustable mirror causes the first incident light to be incident on the surface of the sample along the first optical path at the first incident angle, and the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle; wherein, the position of the second adjustable mirror in the first optical path is the first position, and the position of the first adjustable mirror in the second optical path is the second position.

16. The method of operating the optical system according to claim 15, characterized in that, The process of directing the second incident light along the first optical path to the surface of the sample at the first incident angle via the first adjustable mirror includes: after directing the second incident light to a first position via the first adjustable mirror, the second incident light then directs the second incident light along the first optical path to the surface of the sample at the first incident angle. The method of directing the first incident light along the second optical path to the surface of the sample at the second incident angle via the second adjustable mirror includes: after directing the first incident light to the second position via the second adjustable mirror, the first incident light then directs the first incident light along the second optical path to the surface of the sample at the second incident angle.

17. The method of operating the optical system according to claim 16, characterized in that, If the incident directions of the first incident light and the second incident light are different when they are incident on the first position, and the exit direction of the second incident light along the first optical path after it is incident on the first position is different from the incident direction of the first incident light at the first position, the second adjustable mirror can be rotated. The method of using the second adjustable mirror to cause the first incident light to be incident on the surface of the sample along the first optical path at the first incident angle includes: moving the second adjustable mirror into the first optical path and placing it at the first angle, wherein the first incident light is reflected by the second adjustable mirror and then incident on the surface of the sample along the first optical path at the first incident angle. The second incident light is incident on the surface of the sample along the first optical path at a first incident angle by means of the second adjustable mirror: moving the second adjustable mirror into the first optical path and placing it at a second angle, and the second incident light is incident on the sample surface at the first incident angle after being reflected by the second adjustable mirror. The method of directing the first incident light along the second optical path to the surface of the sample at the second incident angle via the second adjustable mirror includes: positioning the second adjustable mirror at a third angle in the first optical path, the first incident light being reflected by the second adjustable mirror and then incident at the second position, and subsequently, the first incident light being incident along the second optical path to the surface of the sample at the second incident angle. The second adjustable mirror is also movable. Allowing the first incident light to be incident on the surface of the sample along the second optical path at the second incident angle via the second adjustable mirror includes: moving the second adjustable mirror out of the first optical path, allowing the first incident light to bypass the second adjustable mirror and be incident at the second position, and then allowing the first incident light to be incident on the surface of the sample along the second optical path at the second incident angle; or, allowing the first incident light to be incident on the surface of the sample along the first optical path at the first incident angle via the second adjustable mirror includes: moving the second adjustable mirror out of the first optical path, allowing the first incident light to bypass the second adjustable mirror and then be incident on the surface of the sample along the first optical path at the first incident angle. And / or, If the first incident light and the second incident light are incident in different directions when they reach the second position, and the exit direction of the first incident light along the second optical path after it reaches the second position is different from the incident direction of the second incident light at the second position, the first adjustable mirror can be rotated. The method of directing the second incident light along the second optical path to the surface of the sample at the second incident angle via the first adjustable mirror includes: moving the first adjustable mirror into the second optical path and placing it at the fourth angle, wherein the second incident light is reflected by the first adjustable mirror and then directed along the second optical path to the surface of the sample at the second incident angle. The method of directing the first incident light to the surface of the sample along the second optical path at a second incident angle via the first adjustable mirror includes: moving the first adjustable mirror into the second optical path and placing it at a fifth angle, wherein the first incident light is reflected by the first adjustable mirror and then directed along the second optical path to the surface of the sample at a second incident angle. The method of directing the second incident light along the first optical path to the surface of the sample at the first incident angle via the first adjustable mirror comprises: positioning the first adjustable mirror at a sixth angle in the second optical path; the second incident light being reflected by the first adjustable mirror and then incident at the first position; subsequently, the second incident light being incident along the first optical path to the surface of the sample at the first incident angle. The first adjustable mirror can also be moved. Allowing the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle via the first adjustable mirror includes: moving the first adjustable mirror out of the second optical path, allowing the second incident light to bypass the first adjustable mirror and be incident on the first position, and then allowing the second incident light to be incident on the surface of the sample along the first optical path at the first incident angle; or, allowing the second incident light to be incident on the surface of the sample along the second optical path at the second incident angle via the first adjustable mirror includes: moving the first adjustable mirror out of the second optical path, allowing the second incident light to bypass the first adjustable mirror and then be incident on the surface of the sample along the second optical path at the second incident angle.

18. The method of operating the optical system according to claim 15, characterized in that, If the first incident light, after being incident on the first position, exits along the first optical path in the same direction as the second incident light when it is incident on the first position; and / or, the first incident light, after being incident on the second position, exits along the second optical path in the same direction as the second incident light when it is incident on the second position. The first adjustable mirror is placed in a first state, and the second adjustable mirror is placed in a second state. The first incident light is incident on the surface of the sample along the first optical path at a first incident angle through the second adjustable mirror, while the second incident light is incident on the surface of the sample along the second optical path at a second incident angle through the first adjustable mirror. The first adjustable mirror is placed in the third state, and the second adjustable mirror is placed in the fourth state. The second incident light is incident on the surface of the sample along the first optical path at the first incident angle through the second adjustable mirror, while the first incident light is incident on the surface of the sample along the second optical path at the second incident angle through the first adjustable mirror.

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